Hey guys, I'm a new member to this website, but i've been trying to troubleshoot a problem with my 1994 Mazda Miata. What's wrong is that there is a constant rattle that is dull at high rpms in first gear, but becomes more apparent in higher gears, no matter what rpms. I have ruled out that it is a heat shield, because i removed the heat shield over the exhaust manifold and the rattling continued. Could it possibly be an EGR problem? Or a crack in the headers? I honestly think it's the headers but I hope it isn't... don't want to spend too much money.